Updating a digital map

Abstract

A method updates a digital map stored in a vehicle. The updated map is consistent and at the same time the amount of data transferred is small. The map has a plurality of map objects, wherein an object identifier and a version number are associated with each map object. The method determines a first map object to be updated, transfers a request data set for updating the first map object from the vehicle to a central computer, wherein the request data set includes the object identifier and the version number of the first map object, determines a change operation of the first map object with respect to the version of the first map object that is indicated by the sent version number, determines further map objects changed in the change operation, assembles an update data set, and transfers the update data set from the central computer to the vehicle.

What is claimed is: 
     
       1. A method for updating a digital map stored in a vehicle, wherein the digital map comprises a multiplicity of map objects, wherein an object identifier and a version number are assigned to each map object, the method comprising the steps of:
 determining, by the vehicle, a first map object to be updated; 
 transmitting a request data record for updating the first map object from the vehicle to a central computer, wherein the request data record comprises the object identifier and the version number of the first map object; 
 determining, by the central computer, an operation for changing the first map object in comparison with that version of the first map object which is identified by the transmitted version number; 
 performing the operation for changing the first map object and incrementing the version number of the first map object; 
 determining, by the central computer, further map objects that are dependent on the first map object and that are changed or added as a result of the change operation of the first map object, wherein the further map objects are changed or added in order to ensure a consistency of the digital map in conjunction with the change operation of the first map object and the respective version number of each of the further map objects is incremented or created; 
 compiling, by the central computer, an update data record consisting of:
 (i) a current version of the first map object, 
 (ii) the version number of the current version of the first map object, and 
 (iii) the respective object identifier and the respective version number of each of the further map objects; and 
 
 transmitting the update data record from the central computer to the vehicle. 
 
     
     
       2. The method as claimed in  claim 1 , further comprising the steps of:
 comparing those version numbers of the further map objects which are contained in the update data record with the version numbers of the further map objects contained in the digital map stored in the vehicle; 
 determining the further map objects to be updated; and 
 updating the further map objects. 
 
     
     
       3. The method as claimed in  claim 1 , wherein the method is carried out iteratively until no further map objects to be updated have been determined. 
     
     
       4. The method as claimed in  claim 1 , wherein the step of determining the first and/or further map objects to be updated comprises determining the map objects:
 (i) in a predetermined radius around a location of the vehicle, and/or 
 (ii) along a route from a location of the vehicle to a destination, and/or 
 (iii) within a corridor of a predetermined width around a route from a location of the vehicle to a destination. 
 
     
     
       5. A vehicle, comprising:
 a control device for updating a digital map stored in a vehicle, wherein the digital map comprises a multiplicity of map objects, and further wherein an object identifier and a version number are assigned to each map object, wherein 
 the control device is operatively configured to execute a program to:
 determine a first map object to be updated; 
 transmit a request data record for updating the first map object from the vehicle to a central computer, wherein the request data record comprises the object identifier and the version number of the first map object; and 
 receive an update data record from the central computer to the vehicle after the central computer performs an operation for changing the first map object and increments the version number of the first map object, wherein the update data record consists of: 
 (i) a current version number of the first map object, 
 (ii) a version number of the current version of the first map object, and 
 (iii) a respective object identifier and a respective version number of each of further map objects that are dependent on the first map object and that are changed or added as a result of updating the first map object, wherein the further map objects are changed or added in order to ensure a consistency of the digital map in conjunction with the change operation of the first map object and the respective version number of each of the further map objects is incremented or created. 
 
 
     
     
       6. The vehicle as claimed in  claim 5 , wherein the control device further executes the program to:
 compare those version numbers of the further map objects which are contained in the update data record with the version numbers of the further map objects contained in the digital map stored in the vehicle; 
 determine the further map objects to be updated; and 
 execute the program for the further map objects to be updated. 
 
     
     
       7. The vehicle as claimed in  claim 6 , wherein the control device executes the program iteratively until no further map objects to be updated have been determined. 
     
     
       8. A central computer for updating a digital map stored in a vehicle, wherein the digital map comprises a multiplicity of map objects, and further wherein an object identifier and a version number are assigned to each map object, the central computer comprising:
 a processor configured to execute a program to:
 receive a request data record for updating a first map object from the vehicle to be updated, wherein the request data record comprises the object identifier and the version number of the first map object; 
 determine an operation for changing the first map object in comparison with that version of the first map object which is identified by the transmitted version number; 
 perform the operation for changing the first map object and incrementing the version number of the first map object; 
 determine further map objects that are dependent on the first map object and that are changed or added as a result of the change operation of the first map object, wherein the further map objects are changed or added in order to ensure a consistency of the digital map in conjunction with the change operation of the first map object and the respective version number of each of the further map objects is incremented or created; 
 compile an update data record consisting of:
 (i) a current version of the first map object, 
 (ii) the version number of the current version of the first map object, and 
 (iii) the respective object identifier and the respective version number of each of the further map objects; and 
 
 transmit the update data record to the vehicle. 
 
 
     
     
       9. The method as claimed in  claim 1 , wherein the update data record does not include current versions of the further map objects. 
     
     
       10. The vehicle as claimed in  claim 5 , wherein the update data record does not include current versions of the further map objects. 
     
     
       11. The central computer as claimed in  claim 8 , wherein the update data record does not include current versions of the further map objects.